Adds Endpoint Insights sub-feature privilege (#836)

Resolves #266 by
documenting the new **Endpoint Insights** Elastic Defend sub-feature
privilege.
The related endpoint insights feature, which this privilege enables, was
previously doc'ed in elastic/security-docs#6480.

Preview: [Elastic Defend feature
privileges](https://docs-v3-preview.elastic.dev/elastic/docs-content/pull/836/solutions/security/configure-elastic-defend/elastic-defend-feature-privileges)

Author: natasha-moore-elastic

solutions/security/configure-elastic-defend/elastic-defend-feature-privileges.md

@@ -36,6 +36,7 @@ For each of the following sub-feature privileges, select the type of access you
 |     |     |
 | --- | --- |
 | **Endpoint List** | Access the [Endpoints](/solutions/security/manage-elastic-defend/endpoints.md) page, which lists all hosts running {{elastic-defend}}, and associated integration details. |
+| **Endpoint Insights** |Access [endpoint insights](/solutions/security/manage-elastic-defend/identify-antivirus-software-on-hosts.md) to check if your hosts have third-party AV software installed. |
 | **Trusted Applications** | Access the [Trusted applications](/solutions/security/manage-elastic-defend/trusted-applications.md) page to remediate conflicts with other software, such as antivirus or endpoint security applications. |
 | **Host Isolation Exceptions** | Access the [Host isolation exceptions](/solutions/security/manage-elastic-defend/host-isolation-exceptions.md) page to add specific IP addresses that isolated hosts can still communicate with. |
 | **Blocklist** | Access the [Blocklist](/solutions/security/manage-elastic-defend/blocklist.md) page to prevent specified applications from running on hosts, extending the list of processes that {{elastic-defend}} considers malicious. |